Diazotype materials containing polycyclic light-sensitive fluorene diazonium salts



United States Patent 3,401,038 DIAZOTYPE MATERIALS CONTAINING POLY-CYCLIC LIGHT SENSITIVE FLUORENE DI- AZONIUM SALTS Theodore Panasilr,Vestal, N.Y., and Robert J. Cox, Los

Gatos, Calif assignors to GAF Corporation, a corporation of Delaware NoDrawing. Continuation-impart of application Ser. No. 350,071, Mar. 6,1964. This application Feb. 19, 1965, Ser. No. 434,101

6 Claims. (CI. 96-91) ABSTRACT OF THE DISCLOSURE Light-sensitivediazotype material sensitized with a diazotized -secondaryor7-tertiary-amino-2-primary aminofluorene.

R2 where R and R are hydrogen, alkyl, aryl, substituted alkyl or aryl,or together with the nitrogen form a heterocyclic moiety such asmorpholino or piperidino, and X is an anion, is considered to be due tothe contriibution made by the substituted amino group to resonancesystems such e e R2 R2 ,T his resonance has the eifect of decreasing thenormal frequency of vibration of the molecule, causing it to absorblight of longer wave length which is more practical to generate andhandle in commercially feasible equipment. This absorbed energy thencauses breakdown of the diazo group with release of nitrogen and loss ofability to form azo dyes by coupling.

However, the region of maximum light absorption of thesep-amino-benzenediazonium salts is for the most part 350-400 m,u, stillin the near ultraviolet. Sensitivity of the compounds to more avail-ablelight of still longer wave length might be increased by intensifying thebathochromic or red shif caused by resonance. A possible method ofachieving this is to increase the length of the resonating path, forexample, as follows:

Unfortunately such simple biphenyl systems have so far failed to giveuseful products.

We have ascertained that by using a methylene (CH group as a bridgingmember, polynuclea-r diazonium salts are produced which under suitableconditions of pH exhibit maximum absorptivity in the visible region ofthe spectrum. As a matter of fact some salts were produced which had amaximum absorption at the high wave length of 515 mu. This propertywhich makes the salts purplish in color, giving to them high sensitivityto visible light, provides utility in fields until now practicallyforeclosed to the diazotype system, such as, for example, enlargement oforiginals. Other important characteristics exhibited by this new classof diazotype sensitizers are a closer approximation to a orthochromaticresponse to the visible light of the spectrum, a much softer gradationthan possible with the usual dliazos derived from p-phenylenediaminesand good resistance to wet bleeding of the dye images.

These polycyclic diazonium salts utilizable in our invention are thediazonium salts of amine selected from the group consisting of7-tertiary-amino-2-primary-aminofluorene and 7-secondary aminocompounds. These compounds are useful sensitizers in diazotype materialsof both the land 2- component types.

Typical diazonium salts of 7-substituted amino-Z-primary-amino-fiuorenecompounds having no other groups on the fluorene ring useful in ourinvention can be represented by the following general formulae:

wherein R is hydrogen; alkyl, i.e., methyl, ethyl, propyl, butyl, amyl,or the like; hydroxyalkyl, i.e., hydroxyethyl, hydroxypropyl,hydroxybutyl, or the like; aryl of the benzene series, i.e., phenyltolyl, or the like; aralkyl, such as benzyl phenethyl, or the like; R isalkyl, i.e. methyl, ethyl, propyl, butyl, amyl, or the like;hydroxyalkyl, i.e., hydroxyethyl, hydroxypropyl, hydroxybutyl, or thelike; aryl of the benzene series, i.e., phenyl, tolyl, or the like;aralkyl, such as benzyl, phenethyl, or the like; Z represents the atomsnecessary to complete a 6-rnembered heterocyclic ring, i.e., morpholino,piperidino, piperazino, thiomorpholino, etc. and X is an anion, such ashalogen, i.e., chlorine, bromine, or the like; sulfate, fiuoroborate anddouble salts with zinc chloride, cadmium chloride, tin chloride, and thelike.

The fluorene nucleus of the structures represented above can of coursecontain various innocuous substituents on either of the aromatic rings,i.e., in the l, 3, 4, 5, 6 or 8 position of the fluorene nucleus.Typical substituents of this type include alkoxy groups such as methoxy,ethoxy, propoxy, n-butoxy, tert-butoxy, octadecyloxy, etc.; alkyl groupssuch as methyl, ethyl, propyl, tertiary butyl, 2-ethylhexyl, octadecyl,etc.; halogen such as chloro, bromo, fiuor0,ete.; acyloxy groups such asacetoxy, propionoxy, etc. and the like.

Examples of such compounds are 7--dimethylamino-2- fluorenediazoniumtetrachlorozincate; 7-diethylamino-2- fiuorenediazonium chlorozincate;7-dipropylamino-2-fluorenediazonium chlorozincate;7-amino-N-2-hydroxyethyl- N-methyl-Z-fiuoroenediazonium chlorozincate;7-bis(2-hyd-roxyethyl)amino-2-fluorenediazonium chlorozincate; 7- dibutylamino-2-fluorenediazonium chlorozincate;7-benzylamino-2-fiuorenediazonium chlorozincate; 7-anilino-2-fluorenediazonium chlorozincate; 7-morpholino-2-fluorenediazoniumchlorozincate; 7 dimethylamino-3-methoxy-2-fiuorenediazoniumchlorozincate; 7-diethylamino-4, -dibutoxy-2-fluorenediazoniumchlorozincate; 7-dipropylamino-3-methyl 2 fiuorenediazoniumchlorozincate; 7- morpholino-3-tertiary-butoxy-2 fluorenediazoniumchloroz-incate; 7-benzylamino-2-fiuorenediazonium chlorozincate, and thelike.

The compounds may be prepared by reacting 7-nitro-2- bromo-fiuoren withthe desired amine, i.e., morpholine, dimethylamine, diethylamine,ethanolamine, benzylamine, aniline, or the like, catalytically, reducingthe resulting 7- nitro-N-substituted fiuoren-Z-amine, to 7amino-N-substituted fiuorenQ-a-mine and diazotizing this primary amine.

Typically N,N-dlmethylfluorene-2,7-diamine (J. Org. Chem. 23, 680(1957)) was prepared by the catalytic reduction ofN,N-dimethyl-7-nitro-fluoren-2-amine (J. Org. Chem. 27, 3643 (1962)).

7 dimethylamino-2-fluorenediazonium chlorozinc'ate was prepared bydissolving grams of N,N-dimethylfluorene-2,7-diamine in 167 ml. ofdilute HCl 1:1. The solution was treated with Norit decolorizing carbon,filtered, and the filtrate was cooled in an ice bath.-To the stirredsolution at 0-5 C., 7.4 ml. of sodium nitrite 5 M was added dropwise.The solution was stirred for minutes at 510 C. and treated with 13.4 ml.of zinc chloride solution (66-67%). The resulting mixture was stirredfor 1 hour and the precipitate was then filtered, slurried with acetone,refiltered, and dried under reduced pressure.

The diazonium compounds can be used in one-component diazotype materialin which case development is brought about by passing the exposeddiazotype material through a moist alkaline bath containing the couplingcomponent. They may 'also be employed in two-component diazotypematerial in which development is brought about, after exposure, bytreatment with ammonia.

Any of the couplers normally employed in the manufacture of processingof diazotype materials may be used and, in this connection, reference ismade to 2,3-naphthalenediol; 2-naphthol-3,6-disulfonic acid;phloroglucinol; 1- (7 hydroxy-l-naphthyl)-biguanide;1,8-naphthalenediol; resorcinol; octylresorcinol;3-methy1-l-phenylpyrazolone; a-resorcylic acid; H acid;acetoacetanilide; and the like.

The coating solutions may contain the various adjuncts usual in themanufacture of light-sensitive diazotype materials. These include metalsalts for intensification of the dyestufi? image such as sodium sulfate,zinc sulfate, zinc chloride; stabilizing agents such as thiourea,thiosinamine, naphthalenetrisulfonic acid; acids acting to retardprecoupling in two-component systems such as acetic acid, boric acid,tartaric acid; hygroscopic agents such as glycol, glycerin; wettingagents such as saponin, lauryl sulfate, keryl benzene sulfonate, theoleic acid amide of N-methyl taurine, and the like. The preferred pH,particularly for one-component materials, ranges from 3 to 7, since itis within this range that the maximum sensitivity for visible light isobserved.

The base to which the coating solution is applied may be any of thosepreviously suggested for employment in the diazotype field. Examples ofsuch bases are high-grade rag paper, cotton, rayon, starch-filled cloth,partially hydrolyzed cellulose triacetate film base,polyethyleneterephthalate, and the like.

The invention will be better understood by reference to the followingexample, but it is to be understood that the invention is not restrictedthereto.

EXAMPLE I 7 dimethylamino-2-fiuorenediazonium chlorozincatc was coatedon paper from a solution of 0.7 g. of diazo in 100 ml. of watercontaining 0.25 g. of citric acid. The coating was dried in a steamcabinet for 510 minutes and exposed through a stepwedge to radiationfrom a 100 watt tungsten lamp at distances and exposure times varyingfrom 13 inches and 4 minutes to 5 inches and 'l .'5--minutes. Theexposed paper was developed in a developer of the followingconstitution:

Borax gms 40 Sodium carbonate gms 30 Thiourea gms 20 Phloroglucinol gms8 Resorcinol gms 8 L'auryl sulfate gms 2 Water cc 1000 A goodnon-bleeding image on a clean white background was formed.

A standard moist process paper sensitized with p-amino-N-benzyl-N-ethylbenzenediazonium chlorozincate, coated, exposed, anddeveloped at the same time and in the same way as the above diazotypematerial failed to give an acceptable copy, the background being nearlyas dark as the image area.

EXAMPLE II A portion of the coated paper prepared as described inExample I from 7-dimethylamino-2-fiuorenediazonium chlorozincate wasexposed for 5 minutes to a four-fold enlarged image originated from amulticolored 35 mm. original. Development of the exposed paper as inExample I gave a good positive image. This demonstrates utility incopying an enlarged image, whereas diazo compounds derived fromp-phenylenediamine cannot be utilized in this manner.

EXAMPLE III A sample of the coated paper containing7-dimethylamino-Z-fiuorenediazoniuni chlorozincate was exposed beneath apositive color transparency to mercury arc radiation. It was thendeveloped with an aqueous solution containing 2,3-naphthalenediol andsodium carbonate. The copy thus obtained faithfully reproduced in bluemonochrome all the objects of the multicolored original.

EXAMPLE IV Water cc 70 Ethylene glycol cc 5 Alcohol cc 2 Citric acid gr5 Thiourea gr 5 Zinc chloride gr 5 2,3-dihydroxynaphthalene-6-sulfonicacid gr 3 7-diethylamino-Z-fluorene-diazonium chlorozincate gr 2 Saponingr .1 Water cc The sensitizing solution was coated on high-grade paperand dried. The prints made from these coatings had a considerableenhancement in density when compared to prlnts made with the samecomposition using the diazo from N,N-diethyl-p-phenylenediarnine. 3

EXAMPLE V The procedure is the same as in Example IV excepting there wasused as the sensitizer 7- morpholino-Z-fluorenediazonium chlorozincate.

EXAMPLE v1 The procedure was the same as in Example IV exceptmg therewas used as the sensitizer 7-ani1ina-2-fiu0renediazonium chlorozincate.

EXAMPLE VII The procedure was the same as in Example IV excepting thatthe sensitizer used is 7-bis(2'l1ydroxyethy1) aminc-2-fiuorenediazoniumchlorozincate.

5 EXAMPLE VIII.

The procedure is the same as in Example III excepting that thesensitizer used in 7-bis(Z-hydroxyethyDamino- Z-fiuorenediazonium chlorozincate.

Modifications of the invention will occur to persons skilled in the artand we do not, therefore, intend to be limited in the patent grantedexcept as necessitated by the appended claims.

What is claimed is:

1. A light-sensitive diazotype material comprising a support and alight-sensitive layer thereon, said light sensitive layer containing asthe sensitizer a diazonium s'alt having sensitivity to visible lightwherein said diazonium salt comprises the diazotization product of aprimary amino group of the compounds selected from the group consistingof a 7-secondary-amino-2-primary-amino fluorene and a7-tertiary-amino-2-prim'ary-amino fluorene.

2. A. light-sensitive diazotype material as defined in claim 1 wherein acoupling component is present.

3. A light-sensitive diazotype material containing as the sensitizer 'adiazonium salt having sensitivity to visible light wherein saiddiazonium salt comprises the diazotization product of a 7tertiary-amino-2-primary-aminofluorene.

4. A light-sensitive diazotype material as defined in claim 3 whereinsaid tertiary amino group is dimethylamino group.

5. A light-sensitive diazotype material as defined in claim 4 whereinsaid tertiary amino group is a morpho lino group.

6. A light-sensitive diazotype material as defined in claim 4 whereinsaid tertiary amino group is diethylamino group.

References Cited UNITED STATES PATENTS 8/1946 Sease et a1. 96-75 OTHERREFERENCES NORMAN G. TORCHIN, Primary Examiner.

C. L. BOWERS, Assistant Examiner.

